Philip Glass (born January 31, 1937) is a composer from the United States. His music is frequently described as minimalist, though he prefers to describe himself as a composer of "music with repetitive structures". Although his early, mature music is minimalist, he has evolved stylistically. Currently, he describes himself as a "Classicist", pointing out that he is trained in harmony and counterpoint and studied Franz Schubert, Johann Sebastian Bach and Wolfgang Amadeus Mozart with Nadia Boulanger.